ExampleSmsCallback.php

<?php

class ExampleSmsCallback implements CallbackInterface
{
   
    /**
     * @return string
     */
    public function getTransportName()
    {
        return 'example';
    }

    /**
     * @param Request $request
     *
     * @return ArrayCollection
     */
    public function getContacts(Request $request)
    {
        $contact = $this->getContactFromRequest($request);
        
        $contacts = new ArrayCollection();
        $contacts->set($contact->getId(), $contact);

        return $contacts;
    }

    /**
     * @param Request $request
     *
     * @return \Mautic\SmsBundle\Event\DeliveryEvent
     */
    public function getEvent(Request $request)
    {
        $details = $this->getRequestDetails();
        $deliveryEvent = new DeliveryEvent();
        $deliveryEvent->setTrackingHash($details['trackingHash']);
        if($details['eventType'] === 'delivered'){
        $deliveryEvent->setIsDelivered(true);
        }elseif(if($details['eventType'] === 'failed'){
        $deliveryEvent->setIsFailed(true);
        }

        return $deliveryEvent;
    }
    
    private function getRequestDetails(Request $request){
    // process requests
     return $details;
    }
    
    private function getContactFromRequest(Request $request){
      // process requests
      return $contact;
    
    }


}